Signal recording/reproducing apparatus and method

ABSTRACT

A signal recorder/reproducer comprising an integrated buffer memory  22  having a memory area for a recording system and a memory area for a reproduction system, the allocation of the memory areas being variable, and a system controller  5  to control, via a recording control signal input unit  2  or reproduction control signal input unit  4 , the allocation of the memory areas in the integrated buffer memory  22  depending upon which is designated by the user, a recording or reproduction mode.

This is a continuation of U.S. Ser. No. 09/162,330, filed Sep. 28, 1998now U.S. Pat. No. 6,330,214.

TITLE OF THE INVENTION BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a signal recorder/reproducer forrecording a signal into a recording medium and reproducing a signalrecorded in the recording medium, and a signal recording/reproducingmethod applied the signal recorder/reproducer.

2. Description of Related Art

The video signal recorder/reproducer using an optical disc, for example,as the recording medium, has to include buffer memories for recordingand reproduction systems, respectively, to compensate a latency orwaiting time caused by a track jump, seek, etc. of an optical discdrive.

In the conventional video signal recorder/reproducer, the buffermemories include two, one for the recording system and one for thereproduction system, as mentioned above, either of which is usedaccording to which is designated by the user, recording mode orreproduction mode.

For the video signal recorder/reproducer, it has been demanded more andmore to reproduce any portion of an already recorded video signal whilerecording a video signal contiguous to the recorded video signal.

To this end, the response of the reproduction system of the apparatusshould be improved. However, since in the conventional video signalrecorder/reproducer, the separate buffer memories for the recordingsystem and reproduction system are used in the recording mode andreproduction mode, respectively, the method of controlling the memoryand hardware structure are complicated and the buffer memory for therecording system cannot be used for the reproduction system. Therefore,another buffer memory has to be additionally provided for thereproduction system to improve the response of the reproduction system.

SUMMARY OF THE INVENTION

Accordingly, the present invention has an object to overcome theabove-mentioned drawbacks of the prior art by providing a signalrecorder/reproducer having a simplified hardware configuration andadapted to suppress underflow and overflow possibly occurring in amemory means, and a signal recording/reproducing method applied in thesignal recorder/reproducer.

The above object can be achieved by providing a signalrecorder/reproducer to record a signal into a recording medium andreproduce a signal recorded in the recording medium, comprising:

integrated memory means having memory areas for a recording system andreproduction system, respectively, of which the allocation is variable;

controlling means for controlling the allocation of the memory areas ofthe integrated memory means depending upon in which mode the apparatusis to be, recording or reproduction mode.

According to an aspect of the present invention, the controlling meanscontrols the integrated memory means to use the memory areas only forthe recording system when the apparatus is in the recording mode whileusing them only for the reproduction system when the apparatus is in thereproduction mode.

According to another aspect of the present invention, the controllingmeans controls the integrated memory means to use the memory areas forthe recording and reproduction systems, respectively, when the apparatusis in a simultaneous recording/reproduction mode.

According to another aspect of the present invention, an overflow signaldeveloped in the memory area for the recording system when the apparatusis in a simultaneous recording/reproduction, is written into the memoryarea allocated to the reproduction system under the control of thecontrolling means. The integrated memory means is used for data edition.

The above object can also be achieved by providing a method of recordinga signal into a recording medium and reproducing a signal recorded inthe recording medium, wherein allocation of a memory area for arecording system and memory area for a reproduction system in a memoryunit is variable depending upon in which mode the apparatus is to be,recording or reproduction mode.

According to another aspect of the present invention, the memory areasin the memory unit are used only for the recording system when theapparatus is in the recording mode while they are used only for thereproduction system when the apparatus is in the reproduction mode.

According to another aspect of the present invention, the memory areasin the memory unit are used for the recording and reproduction systems,respectively, when the apparatus is in simultaneousrecording/reproduction mode.

According to another aspect of the present invention, an overflow signaldeveloped in the memory area for the recording system when the apparatusis in a simultaneous recording/reproduction mode, is written into thememory area allocated to the reproduction system.

As mentioned above, according to the present invention, the buffermemories for the recording and reproduction systems, respectively, ofthe signal recorder/reproducer are integrated to simplify thecontrolling method and hardware configuration, and when the apparatus isin the reproduction mode, the buffer memory for the recording system isallocated for the reproduction system to improve the response of thereproduction system without any additional buffer memory used in theapparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

These objects and other objects, features and advantages of the presentintention will become more apparent from the following detaileddescription of the embodiments of the present invention when taken inconjunction with the accompanying drawings, of which:

FIG. 1 is a schematic block diagram of the embodiment of the videosignal recorder/reproducer according to the present invention;

FIG. 2 is a detail block diagram showing in detail the configuration ofan essential portion of the video signal recorder/reproducer in FIG. 1;

FIG. 3 is a detail block diagram of another essential portion of thevideo signal recorder/reproducer in FIG. 1;

FIG. 4 graphically illustrates an example of access to memory forrecording of video signal by the video signal recorder/reproducer inFIG. 1;

FIG. 5 graphically illustrates another example of access to memory forrecording of video signal by the video signal recorder/reproducer inFIG. 1;

FIG. 6 graphically illustrates another example of access to memory forreproduction of video signal by the video signal recorder/reproducer inFIG. 1;

FIG. 7 graphically illustrates an example of access to memory forsimultaneous recording and reproduction of video signal by the videosignal recorder/reproducer in FIG. 1;

FIG. 8 is graphically illustrates another example of access to memoryfor simultaneous recording and reproduction of video signal by the videosignal recorder/reproducer in FIG. 1;

FIGS. 9A-9D graphically illustrates an example of access to memory foredition (splicing IN point) by the video signal recorder/reproducer inFIG. 1;

FIGS. 10A-10E graphically illustrates an example of access to memory foredition (splicing OUT point) by the video signal recorder/reproducer inFIG. 1;

FIG. 11 is a block diagram of a variant of the video signalrecorder/reproducer;

FIG. 12 is a schematic block diagram of the video and audio signalrecorder/reproducer according to another embodiment of the presentinvention;

FIG. 13 is a detail block diagram of the recording system of the videoand audio signal recorder/reproducer in FIG. 12;

FIG. 14 is a detail block diagram of the reproduction system of thevideo and audio signal recorder/reproducer in FIG. 12;

FIG. 15 is a drawing for explanation of memory reallocation whenrecording and reproduction are repeatedly done in the video signalrecorder/reproducer in FIG. 1 or video and audio signalrecorder/reproducer in FIG. 12; and

FIG. 16 shows in detail the memory in FIG. 15 when the memory isreallocated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1, there is illustrated a first embodiment of thepresent invention is a video signal recorder/reproducer adapted torecord a video signal into an optical disc as a recording medium set inan optical disc drive 1 by converting an input analog video signal to adigital video signal and band-compressing the digital video signal ordirectly band-compressing the input digital video signal, and toreproduce a band-compressed digital video signal recorded in the opticaldisc by expanding or decompressing it.

As shown in FIG. 1, the video signal recorder/reproducer comprises anintegrated buffer memory 22 having memory areas for a recording system10 and a reproduction system 30, respectively, whose allocation isvariable, and a system controller 5 to control, via a recording controlsignal input unit 3 or reproduction control signal input unit 4, theallocation of the memory areas in the integrated buffer memory 22according to which is designated by the user, a recording orreproduction mode.

As shown in FIG. 1, the integrated buffer memory 22 has a buffer memory22 a for the recording system 10, and a buffer memory 22 b for thereproduction system 30. These recording and reproduction buffer memories22 a and 22 b are controlled to vary in area by the system controller 5via a memory controller 27. For recording, for example, the recordingbuffer memory 22 a will use the entire integrated buffer memory 22. Forreproduction, the reproduction buffer memory 22 b will use the entireintegrated buffer memory 22. The buffer memory 22 may be adapted so thatfor simultaneous recording and reproduction, each of the recording andreproduction buffer memories 22 a and 22 b will share one half of theintegrated buffer memory 22.

As seen from FIG. 1, the recording system 10 is provided to record ananalog or digital video signal into the optical disc, and thereproduction system 30 is provided to reproduce a digital video signalrecorded in the optical disc.

As shown in FIG. 2. the optical disc 1 has a head 1 b which records adigital video signal by irradiating a recording laser beam to an opticaldisc 1 a and reproduces a digital video signal by irradiating areproducing laser beam to the optical disc 1 a, and a spindle motor Icto spin the optical disc 1 a. The head 1 b and spindle motor 1 c arecontrolled by a disc/head controller 2.

The recording system 10 is configured and has functions as will bedescribed herebelow. Namely, the recording system 10 comprises a videosignal processor 14 to process a video signal from an analog VTR, forexample, a camera signal processor 15 to process a signal picked up by acamera system, a tuner 16 to process a broadcasted video signal receivedby an antenna, a video signal selector 17 to select a video signal fromeach of these signal processors, a video signal A/D converter 18 toconvert a selected video signal from the video signal selector 17 to adigital video signal, a video signal controller 20 to select either ofthe converted digital video signal and a direct input digital videosignal, and a video signal band compressor 21 to band-compress a digitalvideo signal from the video signal controller 20.

The video signal input, video signal from the camera system and videosignal from the antenna system supplied from input terminals 11, 12 and13, respectively, are processed by the video signal processor 14, camerasignal processor 15 and tuner signal processor (video system) 16,respectively, and supplied to the video signal selector 17.

The video signal selector 17 is controlled by the system controller 5 toselect a desired video signal from the above input video signals. Thesystem controller 5 is supplied with a recording control signal from arecording control input unit 3. Thus, the desired video signal selectedby the video signal selector 17 is supplied to the video signal A/Dconverter 18.

The video signal A/D converter 18 converts the supplied desired videosignal to a digital signal and supplies it to a digital signalcontroller 20.

In the digital signal controller 20, either the digital video signalfrom the video signal A/D converter 18 or a digital video input suppliedat an input terminal 19 is selected under the control of the systemcontroller 5 according to a setting by the user as in the video signalselector 17, and supplied to the video signal band compressor 21. Thevideo signal band compressor 21 band-compresses the video signal fromthe video signal controller 20 in the MPEG or JPEG mode .

The video signal band-compressed by the video signal band compressor 21is addressed by the memory controller 27 controlled by the systemcontroller 5 via a bus, and stored into the recording buffer memory 22 aof the integrated buffer memory 22.

The digital video signal stored in the recording buffer memory 22 a isrecorded into the optical disc 1 a in the optical disc drive 1 via thebus and data processor 6. In the optical disc drive 1, when a seek ortrack jump takes place, a latency or waiting is caused. In this case,supply of the digital video signal from the integrated buffer memory 22to the optical disc drive 1 has to be stopped.

As shown in FIG. 2, t he data processor 6 comprises a recorded signalprocessor 6 a and a reproduced signal processor 6 b. For signalrecording, the recording signal processor 6 a is activated to process adigital video signal for recording.

The system controller 5 controls the optical disc drive 1 via thedisc/head controller 2 while controlling the operating status of theoptical disc drive 1. The controlled status is informed to a memorycontroller 27 to control data supply from the integrated buffer memory22 correspondingly.

The reproduction system 30 is configured and has functions as will bedescribed herebelow. Namely, the reproduction system 30 comprises avideo signal band expander 31 to band-expand a video signal suppliedfrom the reproduction buffer memory 22 b of the integrated buffer memory22 via the bus, a video signal controller 20 to select a video signalfrom the video signal band expander 31, and a video signal D/A converter32 to convert the video signal selected by the video signal controller20 to an analog video signal.

For reproduction, the optical disc drive 1 has the servos and headmotion thereof controlled by the disc/head controller 2 to supply areproduced video signal to the reproduction buffer memory 22 b via thereproduced signal processor 6 b of the data processor 6. Thereproduction buffer memory 22 b supplies the reproduced video signal tothe video signal band expander 31 proportionally to a balance betweenwrite and read of the reproduced video signal.

The video signal band expander 31 expands the reproduced video signal asprescribed in the MPEG and JPEG and supplies it to the video signalcontroller 20.

The video signal controller 20 is controlled by the system controller 5based on an information derived from a setting by the user and suppliedvia the reproduction control signal input unit 4 to select a digitalvideo signal from the video signal band expander 31 and supply it to thevideo signal D/A converter 32 or an output terminal 34.

The video signal D/A converter 32 converts the digital video signalselected by the video signal controller 20 to an analog video signal andsupplies it to an output terminal 33.

FIG. 3 shows in detail the configuration of the video signal controller20. The video signal controller 20 comprises select switches SW1 andSW2. The select switch SW1 comprises a selectable terminal a to which adigital video signal input is supplied from the input terminal 19, aselectable terminal b to which a digital video signal is supplied fromthe video signal A/D converter 18 via an input terminal 36, a selectableterminal c to which a decoded video signal is supplied from the videosignal band expander 31 (MPEG decoder to decode a signal in the MPEGmode), and a selecting piece d to supply a selection input to the videosignal band compressor 21 (MPEG encoder to encode a signal in the MPEGmode). The select switch SW2 comprises a selectable terminal e to whicha digital video signal is supplied from the input terminal 36, aselectable terminal to which a decoded video signal is supplied from theMPEG decoder 31 (video signal band expander), and a selecting piece g tosupply a selection output to the video signal D/A converter 32 via anoutput terminal 37.

The switches SW1 and SW2 of the video signal controller 20 are selectedunder the control of the system controller 5. More particularly, when auser-defined command supplied to the system controller 5 via therecording control signal input unit 3 is that an external digital videosignal from the input terminal 19 should be designated as input andrecorded into the optical disc 1 a, the selecting piece d of the switchSW1 is connected to the selectable terminal a. When the user-definedcommand is that the converted digital video input should be designatedand recorded into the optical disc 1 a, the selecting piece d isconnected to the selectable terminal b. When the user-defined command isthat any of the above video input and a video data reproduced by theoptical disc drive 1 should be spliced to each other and recorded intothe optical disc 1 a, the system controller 5 controls the time when theselecting piece d is connected to the selectable terminal c. That is, adecoded output from the MPEG decoder 31 is fed back directly to the MPEGencoder 21. Thus, a splicing edition for each frame can be done as willbe described later.

In the conventional video signal recorder/reproducer, a dedicated memoryis provided downstream of the video signal band compressor 21 and also adedicated memory is provided downstream of the video signal bandexpander 31. According to the present invention, however, such memoriesare integrated into the integrated buffer memory 22.

More particularly, in the conventional video signal recorder/reproducer,when signal output from the video signal band compressor 21 increasesduring recording and latency of the optical disc drive 1 is large, thededicated buffer memory for the recording system overflows and thus theconventional video signal recorder/reproducer cannot work normally.According to the present invention, however, the reproduction buffermemory 22 b serves as the recording buffer memory 22 a under the controlof the system controller 5 even in such a case. Namely, the area of thereproduction buffer memory 22 b adds to that of the recording buffermemory 22 a.

Also in the conventional video signal recorder/reproducer, when seek andtrack jump take place frequently during reproduction , the dedicatedbuffer memory for the reproduction system will underflow. According tothe present invention, however, the recording buffer memory 22 a servesas the reproduction buffer memory 22 b in this case. That is, the areaof the recording buffer memory 22 a adds to that of the reproductionbuffer memory 22 b.

FIG. 4 shows an example of access to the integrated buffer memory 22 forrecording. In the conventional video signal recording/reproducer, sincethe memories are provided for the recording and reproduction systems,respectively, and they are independent of each other, a memory capacityof 2n is only available for recording or reproduction. According to thepresent invention, however, the recording buffer memory 22 a andreproduction buffer memory 22 b are integrated into the integratedbuffer memory 22 and the recording buffer memory 22 a can serve as thereproduction buffer member 22 b, or vice versa as necessary. Thus, amemory capacity of 4n (2n+2n) is available for recording andreproduction.

Suppose now that the integrated buffer memory 22 currently storessignals from the video signal band compressor 21 up to a memory capacityof n and recording starts when signal is stored up to the capacity of n.

In Phase 1, recording is done. Signal is output from the integratedbuffer memory 22 and written into the optical disc 1 a in the opticaldisc drive 1. The transfer rate for write into the optical disc 1 a issupposed here to be double the transfer rate for input from the videosignal band compressor 22 into the integrated buffer memory 22. Forexample, when the transfer rate for write from the video signal bandcompressor 21 into the integrated buffer memory 22 is 10 Mbps, thetransfer rate for write into the optical disc 1 a is 10 Mbps.

In Phase 2, the integrated buffer memory 22 is empty and so the opticaldisc drive 1 shifts to a waiting state for a time including a latency orwaiting time caused when the head is moved for write to another area.During this wait or latency, the video signal band compressor 21supplies a signal to the integrated buffer memory 22. When the signal isstored there up to the memory capacity of n, the integrated buffermemory 22 shifts to recording in Phase 3. Normally, the capacity of theintegrated buffer memory 22 depends upon a longest or worst latency orwaiting time caused by the head movement, so the integrated buffermemory 22 will not overflow.

However, if the servo of the optical disc drive 1 does not work normallydue to a vibration or shock or if no write becomes possible into theoptical disc 1 a due to a scratch or dust thereon, the latency orwaiting time will be longer than normal. In this case, the time requiredfor write into the integrated buffer memory 22 will be longer andoccupancy of the integrated buffer memory 22 will be larger as in Phase4.

Conventionally, the recording memory capacity is 2 n. Therefore, as seenfrom FIG. 4, no recording is possible for a hatched portion shown inFIG. 4 that exceeds the capacity of 2 n. According to the presentinvention, however, no overflow of the integrated buffer memory 22 willtake place so that recording can be done continuously.

In Phase 5, recording is done at a transfer rate double that at whichrecording has so far been done. (40 Mbps), for example, to record toomany signals not yet stored in Phase 4 in a same length of time as hasbeen.

FIG. 5 shows another example of memory access for recording. The memoryaccess up to Phase 3 in this example is the same as in the example inFIG. 4. When signal output from the video signal band compressor 21becomes two times larger than ever for any reason in Phase 4, theconventional buffer memory will overflow as mentioned above. The reasonpossibly includes input of a picture of many scene changes, digitalinput of a compressed signal of which the bit generation rate is unknownor input at a higher transfer rate than set for compression. Accordingto the present invention, however, since the recording buffer memory 22a can be of 4 n in capacity, the buffer memory will not overflow so thatrecording can be done continuously.

FIG. 6 shows an example of memory access for reproduction. A buffermemory is provided for each of the recording and reproduction systems,each memory having a capacity of 2 n. In the present invention, theintegrated buffer memory 22 has a capacity of 4 n for reproduction.

Suppose now that when the integrated buffer memory 22 has output up to 3n of signal to the video signal band expander 31, the optical disc drive1 starts reproduction. In Phase 1, reproduction is effected. Signal isread from the optical disc 1 a and written into the integrated buffermemory 22. This signal write is done at a transfer rate double that foroutput from the integrated buffer memory 22 to the video signal bandexpander 31. For example, when output to the video signal band expander31 is done at a transfer rate of 10 Mbps, the read transfer to theoptical disc 1 a is done at a rate of 20 Mbps. In Phase 2, theintegrated buffer memory 22 becomes full, the optical disc drive 1shifts to waiting status for a time including a latency caused by thehead movement for read from another area.

For this latency, the integrated buffer memory 22 supplies signal to thevideo signal band expander 31 up to 3 n. Then the memory access shiftsto reproduction in Phase 3. Normally, the capacity of the integratedbuffer memory 22 is determined based on a longest or worst latencycaused by the head movement, so the integrated buffer memory 22 will notoverflow.

However, if the servo of the optical disc drive 1 does not work normallydue to a vibration or shock or if no read becomes possible into theoptical disc 1 a due to a scratch or dust thereon, the latency orwaiting time will be longer than normal. In this case, the time requiredfor output will be longer as in Phase 4 and the residual data in theintegrated buffer memory 22 will be reduced to 1.5 n.

Conventionally, the recording memory capacity is 2 n. Therefore, as seenfrom FIG. 4, no reproduction is possible for a hatched portion shown inFIG. 4 that exceeds the capacity of 2 n. According to the presentinvention, however, since the reproduction buffer memory 22 b has acapacity of 4 n, it will no overflow so that reproduced signal can becontinuous.

In Phase 5, reproduction is done at a transfer rate double that at whichrecording has so far been done (40 Mbps), for example, to make up signaltoo much reduced in Phase 4.

FIG. 7 shows an example of memory access for simultaneousrecording/reproduction. For the simultaneous recording/reproduction, thememory access is controlled with the integrated buffer memory 22 dividedinto two sections. Namely, one section of 0 to 2 n is used as therecording buffer memory 22 a while the other section of 2 n to 4 n is asthe reproduction buffer memory 22 b.

In Phase 1, memory access is done for recording. The recording systemwill write signal into the optical disc drive 1 until the used capacityof the recording buffer memory 22 a starts at 2n and becomes 0.Simultaneously, the reproduction system will output signal to the videosignal band expander 31. In Phase 2, the head is moved (latency orwaiting time), so the recording system stops write to the optical discdrive 1 while the reproduction system keeps the preceding status. InPhase 3, memory access is done for reproduction. The recording systemwill maintain the preceding status while the reproduction system willread signal from the optical disc drive 1 and write it into thereproduction buffer memory 22 b. Phase 4 is a latency again. Therecording system will maintain the preceding status while thereproduction system will stop reading. Subsequently, the operations inPhases 1 to 4 are repeated to implement the simultaneousrecording/reproduction.

FIG. 8 shows an example of memory access when an unexpected latencytakes place during the simultaneous recording/reproduction. The memoryaccess in Phases 1 to 3 are similar to those having been described withreference to FIG. 7. In Phase 4, if no recording/reproduction ispossible for any reason, the buffer memory in the conventional signalrecorder/reproducer would overflow in a hatched area A in FIG. 8,recording be interrupted, the memory overflow in a hatched area C andreproduction be interrupted. According to the present invention, sincethe recording and reproduction buffer memories are integrated into theintegrated buffer memory 22, the overflow in the hatched area A can beprevented by using a hatched area B for the reproduction system.Although the overflow in the hatched area C cannot be prevented sincethere is no data, recording will not be interrupted so that the buffermemory can be controlled with a priority to the recording.

In the video signal recorder/reproducer according to the presentinvention, an MPEG encoder and MPEG decoder are used as the video signalband compressor 21 and video signal band expander 31, respectively, asshown in FIG. 3 so that a splicing edition can be implemented for eachframe forming together a GOP.

A video signal compressed in the MPEG encoding mode has a GOP structure.Generally, for edition for each frame, the video signal is convertedback to an analog signal once, and the analog signal is re-encoded fromthe beginning. In this embodiment, the time of an image degradation dueto re-encoding of only a GOP at the splicing-edited point can beminimized by making a feedback from the MPEG decoder 31 to the MPEGencoder 21.

The IN point for the splicing edition will be explained herebelow withreference to FIG. 9. For the convenience of the explanation, it issupposed that a video data reproduced from the optical disc 1 a isspliced with a converted digital video signal supplied from the videosignal A/D converter 18 to the selectable terminal b of the switch SW1of the video signal controller 20 via the input terminal 36.

Namely, it is supposed that a data B4 in GOP2 in the data in the opticaldisc 1 a shown in FIG. 9A is spliced with a data Ba and subsequent dataof an input data which will be an A/D-converted output shown in FIG. 9B.In this case, the data B4 in GOP2 is taken as P picture to produce a GOPconsisting of data B1, B2, I3, P4 (B4).

To decode the data B1 and B2 in GOP2, a data P15 is required, and todecode the data P15, a data 13 is required. Therefore, for splicingbetween data B4, it is necessary to acquire a data in the optical discfrom GOP1 preceding GOP2 by one GOP.

First, the selecting piece d of the switch SW1 of the video signalcontroller 20 is connected to the selectable terminal c under thecontrol of the system controller 5. Thus, a decoded output from the MPEGdecoder 31 is supplied to the MPEG encoder 21 via the switch SW1.

The MPEG encoder 21 starts re-encoding at I3 of GOP2 as shown in FIG.9C. When B4 is changed to P4, the system controller 5 will connect theselecting piece d of the switch SW1 to the selectable terminal b.

The MPEG encoder 21 continuously encodes an input data beginning with Baas shown in FIG. 9B to produce Ic, Ba and Bb as shown in FIG. 9C. SinceBa and Bb provide only a rearward prediction, a closed GOP flag is addedto the GOP header. Thereby, MPEG encoder outputs I3, B1, B2 and P4 canbe followed by MPEG encoder outputs Ic, Ba, Bb, Pf, . . . and the datathus edited can be recorded into the optical disc drive 1 as shown inFIG. 9D.

If the MPEG encoder 21 and MPEG decoder 31 operate asynchronously witheach other, the vertical sync signal will be discontinuous when theswitch SW1 is operated, resulting in an irregular splice point. To avoidthis, the MPEG encoder 21 and MPEG decoder 31 are operated synchronouslywith each other to implement a continuous splice point.

An example of memory access at the edition (splicing edition IN point)will be described herebelow. It is supposed here that the transfer ratefor read/write from/to the optical disc drive 1, transfer rate foroutput from the MPEG encoder 21 (also a transfer rate for write into therecording buffer memory 22 a) and transfer rate for input to the MPEGdecoder 31 (also a transfer rate for read from the reproduction buffermemory 22 b) are all the same (10 Mbps, for example).

First, in “Reproduction 1”, data is read from the optical disc 1 a atthe beginning of a GOP (GOP1) preceding an GOP (GOP2) in which a frameto be spliced exists), and written into the reproduction buffer memory22 b.

Next, when data have been cumulated or stored to some extent in thereproduction buffer memory 22 b, it is output to the MPEG decoder 31 in“Reproduction 2”. It is supposed here that there is no input/outputsignal delay of the MPEG decoder 31. In “Reproduction 2”, write to andread from the reproduction buffer memory 22 b take place simultaneouslyand the read and write transfer rates are same as each other, so thememory capacity will not change.

Next, in “Waiting 1”, if a latency or wait is caused during the headmovement because GOP1 and GOP2 are continuously write in the opticaldisc 1 a or for any other reason, the optical disc drive 1 will supplyno further data to the reproduction buffer memory 22 b but supply datato the MPEG encoder 31 alone, so that the memory capacity will besmaller.

In “Reproduction 1” and “Recording/reproduction 1”, the reproductionbuffer memory 22 b will work as in “Reproduction 2”.

When the optical disc drive 1 reads video signal up to B4 of GOP2necessary for re-encoding, the reproduction stops since the subsequentdata are not required. However, the reproduction buffer memory 22 b willcontinuously output data to the MPEG decoder 31 down to end of B4 asshown in “Recording/reproduction 2”.

Thereafter, the reproduction buffer memory 22 b will make no accessuntil reproduction is resumed (“Waiting 2”, “Recording 1” and “Recording2”). The recording buffer memory 22 a will wait with no access untilrecording is started (“Reproduction 1”, “Reproduction 2”, “Waiting 1”and “Reproduction 3”).

Next, immediately after the selecting piece d of the switch SW1 isconnected to the selectable terminal c and the MPEG encoder 21 outputs are-encoded signal, the recording buffer memory 22 a will start writingand cumulate signals to some extent (“Recording/reproduction 1”,“Recording/reproduction 2” and “Waiting 2”

When write to the optical disc drive 1 starts as shown in “Recording 1ε,the capacity of the recording buffer memory will not vary since supplyand consumption are same as each other.

After output from the MPEG encoder 21 is complete, all data remaining inthe recording buffer memory 22 a are completely written into the opticaldisc drive 1 as shown in “Recording 2”.

Next, the splicing edition OUT point for each frame will be describedherebelow with reference to FIG. 10. Description will be made of asplicing of B11 and subsequent data in the optical disc shown in FIG.10A to after Pf in an input data being an output from the A/D converter18 shown in FIG. 10C. The input data is a converted digital video signalsupplied from the video signal A/D converter 18 to the selectableterminal b of the switch SW1 of the video signal controller 20 via theinput terminal 36.

In this case, the MPEG encoder 21 will re-encode B11 to P17 and providethe re-encoded data as shown in FIG. 10C. Namely, since the selectingpiece d of the switch SW1 is connected to the selectable terminal b, theMPEG encoder 21 outputs Ic, Ba, Bb, Pf, Bd and Be to the optical discdrive 1 as shown in FIG. 10D. When the encoding by the MPEG encoder 21and recording in the optical disc drive 1 have proceeded so far, thesystem controller 5 will connect the selecting piece d of the switch SW1to the selectable terminal c and at the same time the reproduction fromthe optical disc 1 a starts and so the optical disc drive 1 supplies theMPEG decoder 31 with data after the splice point B11.

The MPEG encoder 21 will re-encode data after B11 of MPEG-decoded outputshown in FIG. 10B to remake the data into I13, B11, B12, . . . Theoutput from the MPEG encoder 21, as shown in FIG. 10D, is a data to bewritten as shown in FIG. 10E and written into the optical disc drive 1.

Since the data B11 and B2 provide only a rearward prediction, a closedGOP flag is added to the GOP header. Also, since B16 and B17 andsubsequent data in GOP cannot be decoded, a broken link flag is added tothe GOP header.

A memory access for this edition (splicing edition OUT point) will bedescribed herebelow with reference to FIG. 10. Suppose that theconditions of memory access are same as those shown in FIG. 9.

First, in “Reproduction 1” data is read from the optical disc 1 a at thebeginning of a GOP (GOP1) preceding an GOP (GOP2) in which a frame to bespliced exists), and written into the reproduction buffer memory 22 b.

Next, when data have been cumulated or stored to some extent in thereproduction buffer memory 22 b, it is output to the MPEG decoder 31(“Reproduction 2” “Recording/reproduction 1, 2, 3”. It is supposed herethat there is no input/output signal delay of the MPEG decoder 31. In“Reproduction 2” write to and read from the reproduction buffer memory22 b take place simultaneously and the read and write transfer rates aresame as each other, so the memory capacity will not change.

In “Recording/reproduction 4” read from the optical disc drive 1 hasbeen completed. Therefore, output is made only to the MPEG decoder 31 inthis case. Memory access is completed in “Recording 2”

No access is made to the recording buffer memory 22 a until recording isstarted. The memory 22 a waits for access (“Reproduction 1” and“Reproduction 2”.

Next, the selecting piece d of the switch SW1 is connected to theselectable terminal b, output from the video signal A/D converter 18 issupplied to the MPEG encoder 21 via the input terminal 36, encoded datais supplied from the MPEG encoder 21 is delivered, and at the same time,write to the recording buffer memory 22 a is started as shown in“Recording/reproduction 1”. Data is cumulated into the memory 22 a tosome extent.

When write into the optical disc 1 a of the optical disc drive 1 starts,data supply and consumption are same as each other so that the memorycapacity will not vary (“Recording/reproduction 2, 3, 4” and “Recording2”.

After completion of the output from the MPEG encoder 21, the opticaldisc drive 1 completes write, into the optical disc 1 a, of all dataremaining in the recording buffer memory 22 a as in “Recording 3”.

The reason why the write into the optical disc 1 a is completed at I18of GOP3 is that a broken link flag has to be added since B16 and B17 inGOP3 cannot be predicted from P17. B16 and B17 can be predicted byreading I18.

Since the video signal recorder/reproducer shown in FIG. 1 adopts theintegrated buffer memory 22, the edition in the MPEG mode can beachieved without underflow and overflow.

Note that the video signal recorder/reproducer in FIG. 1 may beconfigured as shown in FIG. 11. Namely, the integrated buffer memory 22may be provided at the video signal band compressor 21 and video signalband expander 31 rather than at the bus 7.

The aforementioned embodiment of the present invention is a video signalrecorder/reproducer for recording/reproduction of video signal. However,the present invention is also applicable to a video and audio signalrecorder/reproducer as shown in FIGS. 12 to 14.

The video and audio signal reproducer/reproducer will be describedherebelow as the second embodiment of the present invention.

As shown in FIG. 12, the video and audio signal recorder/reproducercomprises a recording system 110 and recording buffer memory 160 torecord video and audio signals supplied via input terminals 80 and 90into an optical disc drive 100 as an example of the recording medium,and a reproduction buffer memory 170 and reproduction system 200 toreproduce video and audio signals recorded in the optical disc 1 a shownin FIG. 2 by the optical disc drive 100.

The video and audio signal recorder/reproducer further comprises adisc/head controller 101 to control the spinning speed of the opticaldisc 1 a in the optical disc drive 100 and control an optical head whichirradiates laser beam to the optical disc 1 a to write and read videoand audio signals, a recording control signal input unit 102 to input,via a human interface (not illustrated), a control signal under whichthe video and audio signals is recorded into the optical disc 1 a, areproduction control signal input unit 103 to input, via the humaninterface, a control signal under which the video and audio signals arereproduced from the optical disc 1 a, and a system controller 104 tocontrol the recording and reproduction systems and the controller basedon the recording and reproduction control signals, respectively,supplied from the recording and reproduction control signal input units102 and 103, respectively.

The aforementioned video and audio signal recorder/reproducer basicallyfunctions as will be described herebelow.

First, the recording operation of the apparatus will be described.Namely, video and audio signals supplied via the input terminals 80 and90, respectively, are supplied to the recording system 110 in which theyare processed in predetermined manners, respectively, and supplied tothe recording buffer memory 160. The buffer memory 160 delivers to theoptical disc drive 100 the video and audio signals proportionally to abalance between write and read of the signals. In the optical disc drive100, the video and audio signals are recorded into the optical disc 1 awhile the spinning of the optical disc 1 a and the servos for theoptical head movement are controlled by the disc/head controller 101.

The recording procedure is as will be described below. Namely, when at acontrol unit (not illustrated), the user pushes a record button forselection of the recording mode, the recording control signal input unit102 generates a recording control signal for delivery over the humaninterface to the system controller 104 which in turn will give therecording and reproduction systems and controllers an instructioncorresponding to the recording control signal.

Next, the reproducing operations are as follows. That is, when thereproduction mode is selected, the servos and optical head movement arecontrolled by the disc/head controller 101 in the optical disc drive 100and a reproduced signal is delivered to the reproduction buffer memory170. The reproduction buffer memory 170 will output to the reproductionsystem 200 the reproduced signal proportionally to a relation betweenwrite and read of the signal. The reproduction system 200 processes thereproduced signal in a predetermined manner to provide a video signaland audio signal which are supplied to output terminals 250 and 260,respectively.

The reproducing procedure is as will be described below. Namely, whenthe user pushes a reproduce button for selection of the reproductionmode, the reproduction control signal input unit 103 generates areproduction control signal for delivery over the human interface to thesystem controller 104 which in turn will give the recording andreproduction systems and controllers an instruction corresponding to thereproduction control signal.

Also in the video and audio signal recording/reproducer, the recordingbuffer memory 160 and reproduction buffer memory 170 are integrated intothe integrated buffer memory 150.

Conventionally, the recording buffer memory and reproduction buffermemory are provided independently of each other. Therefore, to improvethe reproduction response, for example, a buffer memory dedicated to thereproduction has to be additionally provided. According to the presentinvention, however, the integrated buffer memory 150 incorporated in thesignal recorder/reproducer allows to simplify the memory control modeand hardware configuration, allocate the reproduction buffer memory 170for the recording system when recording is done or the recording buffermemory 160 for the reproduction system when reproduction is done.Therefore, the reproduction can be done with an improved response andwithout any additional buffer memory dedicated for the reproduction.

Also in the video and audio signal reproducer/reproducer according tothe present invention, when a signal reproduced from the optical disc 1a in the optical disc drive 100 is edited, the edited signal can berecorded into the optical disc 1 a in the optical disc drive 100 byreturning the signal from the reproduction system 200 to the recordingsystem 110.

On the other hand, to physically rearrange a reproduced signal on theoptical disc 1 a in the optical disc drive 100 without editing thesignal, it is recorded into the optical disc drive 1 via the recordingbuffer memory 160.

In the foregoing, the recording and reproduction, effected independentlyof each other, have bee described. For simultaneous recording andreproduction, read and write of a signal to and from the optical disc 1a in the optical disc drive 100 are effected in a time-sharing manner.An interruption of the data resulted from the simultaneous recording andreproduction done in the time-sharing manner can be compensated by theintegrated buffer memory 150. This will be further describedhereinunder.

FIG. 13 shows in detail the configuration of the recording system 110.As shown, the recording system 110 comprises a video signal recordingsystem 111 to process a video signal for recording, and an audio signalrecording system 125 to process an audio signal for recording.

First the video signal recording system 111 will be explained below.Input video signals received at input terminals 81, 82 and 83,respectively, are supplied to a video signal selector 115 afterprocessed by a video signal processor 112, camera signal processor 113and tuner signal processor (video) 114 v, respectively.

The video signal selector 115 selects a desired one of the input videosignals under the control of the system controller 104. The systemcontroller 104 is supplied with a recording control signal from therecording control signal input unit 102 according to a command enteredby the user via a user interface (not shown). The desired video signalselected by the video signal selector 115 is supplied to a video signalA/D converter 116.

The video signal A/D converter 116 converts the desired video signal toa digital signal and supplies it to a video signal controller 117.

Similarly to the video signal selector 115, the video signal controller117 selects one of a digital video signal from the video signal A/Dconverter 117, a input digital video signal from the input terminal 84and a DV input supplied from an input terminal 85 via a DV-mode expander118 under the control of the system controller 104 reflecting a commandentered by the user, and supplies it to a video signal band compressor119.

Note that the DV input refers to a digital video camera input based onthe standard for the home digital video cameras. The DV input isconverted by the DV-mode expander 118 for suitable use in therecorder/reproducer according to the present invention, and thensupplied to the video signal controller 117.

When the recording system 110 edits or otherwise presses a reproducedvideo signal from the reproduction system 200, the video signalcontroller 117 is provided with the reproduced video signal via an inputterminal 87.

The video signal band compressor 119 band-compresses a reproduced videosignal from the video signal controller 117 in the MPEG or JPEG mode,and supplies it to a video signal selector 120.

The video signal selector 120 swaps a compressed digital signal such asin a digital satellite broadcasting/digital TV broadcasting suppliedfrom the input terminal 86 via a compression mode converter 121 and avideo signal from the video signal band compressor 119.

Note that the input compressed digital signal may be a data from acomputer or the like. If the input compressed digital signal does notmatch the recording method adopted in the recorder/reproducer accordingto the present invention, the mode in which the input compressed datahas been compressed is converted to an appropriated one by thecompression mode converter 121.

The video signal selected by the video signal selector 120 is suppliedto a video memory for video system forming the recording buffer memory160. The video system buffer memory 161 supplies the video signal to therecorded data processor 105 proportionally to a relation between writeand read of the video signal with respect to the optical disc 1 a in theoptical disc drive 100.

Next, an audio signal recording system 123 will be described herebelow.An input audio signal, microphone signal and antenna signal received atinput terminals 91, 92 and 93, respectively, are processed by an audiosignal processor 124, microphone input voice processor 125 and tunersignal processor (audio) 114 a, respectively, and then supplied to anaudio signal selector 126.

The audio signal selector 126 selects a desired one of the input audiosignals under the control of the system controller 104. The systemcontroller 104 is supplied with a recording control signal from therecording control signal input unit 102 according to a command enteredby the user via a user interface (not shown). The desired audio signalselected by the audio signal selector 126 is supplied to an audio signalA/D converter 127.

The audio signal A/D converter 127 converts the desired audio signal toa digital signal and supplies it to an audio signal selector 128.

Similarly to the audio signal selector 126, the audio signal selector128 selects one of a digital audio signal from the audio signal A/Dconverter 127, a input digital audio signal from an input terminal 93and a DV input supplied from an input terminal 85 via the DV-modeexpander 118 under the control of the system controller 104 reflecting acommand entered by the user, and supplies it to an audio signalprocessor 129.

When the recording system 110 edits or otherwise presses a reproducedaudio signal from the reproduction system 200, the audio signal selector128 is supplied with the reproduced audio signal via an input terminal94.

As shown, the audio signal processor 129 comprises a buffer memory 130for audio system and a fader 131. When splicing the input digital audiosignals not continuous in the time-base direction to each other, theaudio signal processor 129 adjusts the audio level in the vicinity ofthe splice point correspondingly to a difference in amplitude levelbetween the audio signals to be spliced to each other. When theamplitude level difference between the input digital audio signals to bespliced to each other is larger than predetermined, the fader 131 willnot provide any fading. When the difference is larger thanpredetermined, the fader 131 will make a fading. The fading includes afade-out of the audio level at a preceding portion before the splicepoint, and a fade-in of the audio level at a following portion after thesplice point. The amplitude level difference is detected by the systemcontroller 104. Further, the system controller 104 will allow the fader131 to effect a fading or not depending upon the amplitude leveldifference as mentioned above. The audio signal processor 129 permits tosuppress an uncomfortable noise developed at the splice point duringreproduction.

The digital audio signal output from the audio signal processor 129 issupplied to the audio signal band compressor 132 which band-compressesthe signal in the MPEG audio or AC-3 mode and supplies the compressedsignal to an audio signal selector 133.

The audio signal selector 133 swaps an input compressed digital signalsuch as in a digital satellite broadcasting/digital TV broadcastingsupplied from the input terminal 86 via a compression mode converter 121and an audio signal from the audio signal band compressor 132.

If the input compressed digital signal does not match the recordingmethod adopted in the recorder/reproducer according to the presentinvention, the mode in which the input compressed digital data has beencompressed is converted to an appropriated one by the compression modeconverter 121.

The signal selected by the audio signal selector 133 is supplied to anaudio system buffer memory 162 forming the recording buffer memory 160.Under the control of the memory controller 164, the entire recordingbuffer memory 160 adjusts the length of time of the signals supplied tothe video system buffer memory 161 and audio system buffer memory 162,respectively, from the video signal selector 120 and audio signalselector 133, respectively, while multiplexing the signals (programstream and transport stream in the MPEG system, for example). Headerinformation necessary for the multiplexing (time information, streaminformation, etc.) is supplied from the system controller 104.

The multiplexed signal is supplied to the recorded data processor 105proportionally to a balance between read and write with respect to therecording buffer memory 160 not to cause an overflow or underflow of thememory 160.

For write of a recorded data into the optical disc 1 a in the opticaldisc drive 100, the recorded data processor 105 processes the data bydata rearrangement, addition of error correction code or EFM modulationaccording to a recording format. In the optical disc drive 100, theservos, optical head motion, etc. are controlled by the disc/headcontroller 101 as having previously been described to record the data ina given place.

In addition to the video system buffer memory 161 and audio systembuffer memory 162, The recording buffer memory 160 comprises arearrangement buffer memory 163 buffer memory which is not only used foredition of video and audio signals reproduced by the reproduction system200 but for rearrangement of the signals for recording into the opticaldisc 1 a in the optical disc drive 100.

FIG. 14 shows in detail the configuration of the reproduction system200. As shown, the reproduction system 200 comprises a video signalreproduction system 201 to process, for recording, a video signal readfrom the optical disc 1 a in the optical disc drive 100 and an audiosignal reproduction system 220 to process, for reproduction, an audiosignal read from the optical disc 1 a.

The disc/head controller 101 controls the spinning of the optical discand the tracking and focus servos. A signal read by the optical head issupplied to the reproduced data processor 106.

The reproduced data processor 106 processes the data by EFMdemodulation, data rearrangement, addition of error correction code to areproduction format, and supplies the reproduced data to thereproduction buffer memory 170 via the data bus.

The reproduction buffer memory 170 is integrated with the recordingbuffer memory 160 to form the integrated buffer memory 150.

More particularly, the reproduction buffer memory 170 is adapted tocomprise, a compression mode conversion buffer memory 171 which is to beused for converting the compression mode when the read data is acompressed one, video system 1 buffer memory 172, video system 2 buffermemory 173, audio system 1 buffer memory 174, audio system 2 buffermemory. 175, and a rearrangement buffer memory 176 similar to therearrangement buffer memory 163 included in the recording buffer memory160. The reproduction buffer memory 110 composed of these buffermemories is controlled by a memory controller 164.

A reproduced data from the reproduced data processor 106 is stored intothe reproduction buffer memory 170 under the control of the memorycontroller 164, then subjected to head analysis, demultiplexed anddistributed to each of the buffer memories.

For simultaneous reproduction over two channels of two separate filesrecorded in the optical disc 1 a in the optical disc drive 100, forexample, picture on CH1 is supplied to the video system 1 buffer memory172 while sound on CH1 is supplied to the audio system 1 buffer memory174, and picture on CH2 is supplied to the video system 2 buffer memory173 while sound on CH2 is supplied to the audio system 2 buffer memory175.

Balance between read and write with respect to the reproduction buffermemory 170 are controlled by the system controller 104 and memorycontroller 164 to prevent overflow and underflow of the memory 170, andtiming is adjusted between the picture and sound according to a timeinformation included in the header. The video signal from the videosystem 1 buffer memory 172 is supplied to a video signal band expander202 while the video signal from the video system 2 buffer memory 173 issupplied to the video signal band expander 203.

The video signal band expanders 202 and 203 expand the respective inputvideo signals in the MPEG or JPEG mode and then supply the expandedvideo signals to a video signal selector/synthesizer 204.

The video signal selector/synthesizer 204 is controlled by the systemcontroller 104 based on an informed supplied via the reproductioncontrol signal input unit 103 according to a setting by the user toselect/synthesize the video signal from the video signal band expanders202 and 203 and supply the selected/synthesized video signal to therecording system 110 via the video signal D/A converter 205, DV modeconverter 206 and an output terminal 207. Also, the video signal isdelivered as a digital video signal via an output terminal 208.

The video signal D/A converter 205 converts the digital video signalfrom digital to analog. The analog signal from the converter 205 issupplied to a video signal output unit 209, subjected to chromaconversion and then delivered as a video signal output 1 at an outputterminal 210.

On the other hand, the DV-mode compressor 206 converts the mode of theprocessed signal from the video signal selector/synthesizer 204 to theDV mode and delivers it as a DV output at an output terminal 211. Also,the processed signal supplied from the video signal selector/synthesizer204 to the output terminal 207 is supplied from the input terminal 87 ofthe recording system 110 to the video signal controller 117 where it isprocessed for edition.

For simultaneous delivery of the video signal over both two channels,the video signal from the video signal band expander 203 is supplied tothe video signal D/A converter 212 where it is converted to an analogvideo signal. The analog video signal is delivered as an video signaloutput 2 at an output terminal 214 via a video signal output converter213.

On the other hand, audio signal band expanders 221 and 222 in the audiosignal reproduction system 220 process the respective input audiosignals by expansion in the MPEG audio or AC-3 mode (no expansion forlinear PCM signal) and supply the expanded signals to an audio signalselector/synthesizer 223.

The audio signal selector/synthesizer 223 is controlled by the systemcontroller 104 based on an information supplied via the reproductioncontrol signal input unit 103 according to a setting by the user toselect/synthesize the audio signals from the audio signal band expanders221 and 222 and supply the selected/synthesized audio signals to anaudio signal processor 224.

The audio signal processor 224 comprises an audio system buffer memory225 and a fader 226. When splicing the input digital audio signals notcontinuous in the time-base direction to each other, the audio signalprocessor 224 adjusts the audio level in the vicinity of the splicepoint correspondingly to a difference in amplitude level between theaudio signals to be spliced to each other. When the amplitude leveldifference between the input digital audio signals to be spliced to eachother is larger than predetermined, the fader 226 will not provide anyfading. When the difference is larger than predetermined, the fader 226will make a fading. The fading includes a fade-out of the audio level ata preceding portion before the splice point, and a fade-in of the audiolevel at a following portion after the splice point. The amplitude leveldifference is detected by the system controller 104. Further, the systemcontroller 104 will allow the fader 226 to effect a fading or notdepending upon the amplitude level difference as mentioned above. Theaudio signal processor 224 permits to suppress an uncomfortable noisedeveloped at the splice point during reproduction.

The digital audio signal output from the audio signal processor 224 issupplied to the DV mode compressor 206. Also, the signal is supplied tothe audio signal selector 128 from an output terminal 227 via the inputterminal 94 of the recording system 110 and delivered as a digital audiosignal output at an output terminal 228. Further, it is also supplied toan audio signal D/A converter 229.

The audio signal D/A converter 229 processes by D/A conversion thedigital audio signal from the audio signal processor 224. An analogsignal from the audio signal D/A converter 229 is supplied to an audiosignal processor 230 where it is subjected to various kinds ofprocessing and delivered at an output terminal 231.

For simultaneous delivery of the audio signal over both two channels,the audio signal from the audio signal band expander 222 is supplied toan audio signal D/A converter 232 where it is converted to an analogvideo signal. The analog video signal is subjected to various kinds ofprocessing in an audio signal output processor 233 and delivered at anoutput terminal 234.

The video and audio signals have the compression modes thereof convertedby the compression mode converter 215 via the compression modeconversion buffer memory 171 and delivered as compressed digital outputsignals at an output terminal 216 to an equipment (such as a digitalvideo broadcasting transmitter, digital TV receiver) having video/audioexpanders. The outputs may be connected to a computer or the like.

When recording and reproduction are repeatedly done by the video signalrecorder/reproducer or video and audio signal recorder/reproducer havingbeen described in the foregoing, the program will possibly be segmentedon the optical disc 1 a, resulting in that seamless reproduction ofsignals becomes difficult. If the program is further segmented, thesignals cannot be reproduced as the case may be.

However, the above problem can be solved by rearranging the program asshown in FIG. 15. More particularly, segments A, B, C and D of asegmented program 1 are read and connected to each other in theintegrated buffer memory 22 to continuously record them as shown in FIG.16.

Since the recording/reproduction areas are integrated together, theabove segmentation can be eliminated just by moving the segments withinthe integrated buffer memory 22 or moving the pointer.

According to the present invention, the hardware configuration can besimplified and the occurrence of underflow and overflow of the memory beminimized by integrating the recording and reproduction buffer memoriestogether.

Also memory underflow and overflow can be suppressed during edition aswell.

What is claimed is:
 1. A method of recording a signal into a recordingmedium and reproducing a signal recorded in the recording medium,wherein allocation of a memory area for a recording system and aseparate memory area for a reproduction system in an integrated memoryunit is variable in accordance with a recording and/or reproductionmode.
 2. The method as set forth in claim 1, wherein the memory areas inthe memory unit are used only for the recording system when theapparatus is in the recording mode while they are used only for thereproduction system when the apparatus is in the reproduction mode. 3.The method as set forth in claim 1, wherein the memory areas in thememory unit are used for the recording and reproduction systems,respectively, when the apparatus is in a simultaneousrecording/reproduction mode.
 4. The method as set forth in claim 3,wherein an overflow signal developed in the memory area for therecording system when the apparatus is in the simultaneousrecording/reproduction, is written into the memory area allocated to thereproduction system.
 5. The method as set forth in claim 1, wherein thememory unit is used for data edition.